Track shifting and adjusting device for magnetic sound recorders and reproducers



Sept. 15, 1953 E. KELLER 2,652,259

TRACK SHIFTING AND ADJUSTING DEVICE FOR MAGNETIC SOUND RECORDERS AND REPRODUQERS Filed May 10, 1950 2 Sheets-Sheet 1 77 4 .INVENTOR frnst KeHer' ATTORNEYS Sept. 15, 1953 E. KELLER 2,652,259

TRACK SHIFTING AND ADJUSTING DEVICE FOR MAGNETIC SOUND RECORDERS AND REPRODUCERS Filed May 10, 1950 2 Sheets-Sheet 2:

INVENTOQ 92 Erhsz Keller BY S'Z.Q n

ATTORNEYS Patented Sept. 15, 1953 2,652,259 TRACK SHIFTING AND ADJUSTING DEVICE FOR MAGNETIC REPRODUCERS Ernst Keller, New

chine Tool Works Company, Zurich,

SOUND RECORDERS AND York, N. Y., asslgnor to Ma.-

Oerlikon, Administration Oerlikon, company of Switzerland Switzerland, a

Application May 10, 1950, Serial No. 161,064

4 Claims.

This invention relates to sound recording and reproducing machines, and refers more particularly to magnetic sound recorders and reproducers whereinthe sound carrier usually has the form of a rectangular magnetic sheet similar to a sheet of'writing paper. In the course of the operation of the machine as a recorder the magnetic sheet is wrapped around a drum and is revolved therewith, While a recording head is moved parallel to the drum axis. Thus, the sound is inscribed upon the magnetic sheet in the form of a helix.

Magnetic sheets of this nature are considerably more advantageous in operation than recorders wherein the sound is inscribed upon preformed grooves. One of the advantages of magnetic sheets is that sounds inscribed thereon may be erased by the application of magnets, whereupon the erased portion is available for repeated use in substantially the same manner in which a sheet of paper inscribed in pencil is subject to erasures and corrections.

Another advantage of the magnetic sheet is that after being inscribed it may be folded and sent through the mails in the form of a letter, to he played back by the recipient. Magnetic sheets are light in Weight and quite thin, so that they may be folded, handled, filed and preserved in substantially the same manner as writing paper.

An object of the present invention is to improve sound recording and reproducing machines of the described type through the provision of means which will provide insertions and interlineations upon magnetic sheets bearing an inscribed sound track. r

A further object is to provide sound recording and reproducing machines having means for the provision of a plurality of parallel sound tracks upon the same magnetic sheet.

It is thus apparent that one of the main objects of thepresent invention is to provide such improvements in the sound recording and reproducing machines that the magnetic sheets thereof will be capable of functioning in essentially the same manner as a sheet of paper inserted into an ordinary typewriter now functions. Such typewriter produces upon a sheet of paper a lettering which extends in spaced, parallel rows, and the operator, by the use of backspacing, may make necessary corrections and insert additional writing between the typed lines. Also, the user may fill in the spaces between the lines with a diiferent text, for example, a running translation into a foreign language.

Yet another object of the present invention is to provide means for conveniently adjusting a sound reproducer to the sound track of a magnetic sheet inscribed by a different recording machine.

Other objects of the present invention will 2 become apparent in the course of the following specification.

The objects of the present invention may be realized through the provision of a sound reand reproducing machine which is promeans for shifting in a direction parallel to the longitudinal axis either the spindle oi the recording head or the drum carrying the magnetic sheet, or the recording head itself. Obviously, the same machine may be provided extent of the shifting is not the same as the pitch of the helical sound track. In order to avoid an intersection of sound tracks it is necessary that the shifting of one of the aforesaid parts be less than the pitch of the original sound track.

or reproducing purposes. r

In addition to such shifting, the purpose of which is to create parallel sound tracks, the machine is provided with a device for fine adjustment, the purpose of which is to adjust the machine .to the sound track of a magnetic sheet. It is apparent that the different recording machines may produce difierently located sound and this fine adjustment makes it possible to place the sound head directly in contact with the sound track.

The invention will appear more clearly from the following detailed description, when taken in connection with accompanying drawings showing, by way of example, preferred embodiments of the inventive idea.

In the drawings:

Figure l is a plan view of a recording and reproducing machine with the cover removed, illustrating a method of shifting the spindle;

Figure 2 is a partial section along the lines 2-2 of Figure 1;

Figure 3 is a partial section along the line 3-3 of Figure 1;

Figure 4 is a partial, sectional view of another machineillustrating another method of shifting the spindle;

Figure 5 is a partial section along the line 5-5 of Figure 4;

Figure 6 is a% partial, perspective view, with some parts broken off, of a difierent machine wherein the track shifting is carried out by the drum;

Figure '7 is a partial, side view illustrating mag,- netic means for shifting the drum to different tracks;

Figure 8 is a plan view of the part of the machine shown in Figure 7;

Figure 9 is a top view of a part of a differently constructed machine wherein the shifting of the sound head causes the track shifting;

Figure 10 is a vertical section alongl-l0 of Figure 9; t

Figure 11 is partly a side view and partly'a section on an enlarged scale: of the device shown in Figures-9 and 10;

Figure 12 is a section along the line l2--I2 of Figure 11;

Figure 13 shows diagrammatically and in section a device for carrying out fine adjustment, which may be used inconjunction with the shiftingdevices shown in Figures 6 to 12;

Figure 14 shows a magnetic sheet on a smaller scale.

The sound recording and reproducing machine shown in Figures 1, 2 and 3- includes a substantially hollow rotary drum slot 10 for the insertion of shown in Figure 14.

The drum H is carried upon supporting brackets l2 and [3, which are mounted upon a base plate [4. T-hedrum- H is provided with projecting, preferably knurled, flanges l and I6.

The recording of sound upon the recording sheet 50, and the reproduction of sound, are effected by means of a sound head I'I which, in operation, rests lightly upon the sheet 50 for the purpose of recording sound thereon, or reproducing sound. The sound head I1 is connected to a support I 8 which is mounted upon a plate 5|.

the line a magnetic sheet 59,

Two rollers 52 and 53 are rotatably mounted in the plate 5|, and are carried by a rod I9. It is thus apparent that the rollers 52 and 53 ride upon the rod 19 so that the sound head I! may be shifted in a direction parallel to the axis of the drum H.

The plate 51 alsocarriesa projection 54 which is in engagement with the threads of a threaded spindle 20-. The plate 5lisprovided upon its front endwith a pin or projection 55 to which one end of the wire end of the wire is connected to a spring (not shown) which tends to maintain. it in a stretched condition.

The general principles of this machine are described in greater detail, and claimed, in the copending patent application of'Ernst Keller, Serial No. 118,153, filed September 2'7, 1949.

The rod I9 is attached to two levers 23, which are rotatably supported in bearing plates l2 and 13. The other ends of the levers 23' carry projecting staples 25 which serve as fulcra for two levers 21, only one of which is shown in Figure 1. The levers 21 are joined by a transverse bar 29 which extends the entire-length of the drum H.

It is apparent that a back-spacing movement of the head I! can be efiected conveniently by exerting a short pressure on: the bar 29.- Thisbackspacing movement is described in detail, and

claimed, in the co-pending patent application of Ernst Keller and Hans Sigrist, Serial No. 134,278, filed December 21, 1949, now abandoned.

ll having an elongated 56 is attached; The opposite The spindle 20 is supported at both ends by the same brackets l2 and I3 which support the drum H. A coil spring 62 encloses one end of the spindle 20, and has an and pressing against the bracket 12. The opposite end of the coil spring 62 presses against a flange 63 constituting a part of the spindle 20.

Thedrum ll carries an annular surface H adjacent the flange 15. The opposite end of the drum ll carries a pivot 15 which is firmly connected with a gear wheel 16. The gear 16 meshes with a gear 19, which, in its turn, meshes with the gear 65, which is firmly connected to the spindle 20. The drum H is driven by an electric motor 25a-having, a motor shaft 32, which may be engaged by a wheel 39. The wheel 39 rotates along with a roller 31 which may be engaged by a wheel 42. The wheel 42 may engage the flange H of the drum l I.

The machine: is operated by switching on and off the switch 28 which provides electric current flowing through the wires 3i to the motor 25a. A switch 30' is used to operate a magnet 55 which establishes operative connection between the motor 25 and the drum ll through the motor shaft 32 and the wheels 39, 31, 42 and H. This drive isdescribed in detail, and claimed, in the co-pending patent application of Ernst Keller, Serial No. 149,233, filed March 13, 1950.

As already stated, the drum H has a slot [9 which is used for the insertion of the reinforced top edge 62 of the magnetic sheet 50. Aninclined. roller 92 and resilient fingers to 99- are. used to hold the magnetic sheet 50 in place upon the drum II This construction is described in greater detail, and claimed, in the co-pending patent application of Franz Roggen et al., Serial No. 156,546, filed April 18, 1950.

In the construction shown in Figures 1, 2 and3, the sound track adjustment is produced by mechanical means which shift the spindle 26.

As already stated, one end of the spindle 29 is supported by the bracket 12. Theopposite end of the spindle extends through a bearing 64, which is mounted in the bracket [3. This end of the spindle projects beyond the bracket 13- andcarries the ball 66 along with the gear wheel 65. The ball 66 engages a rigid plate 61 which is rotatably mounted upon a column 68. The plate 61 is'firmly' connected with a plate 69 extending substantially at right angles thereto. It is apparent that the two plates 61 and 69 swivel about the column 68-. A heavy spring '10 is connected to the'plate 69 and to a support H Thus, the spring 10 presses the plate 69- firmly against a sphereshaped end Hill of a threaded rod I01. The rod EM a reduced portion which is firmly connected to a knob 21a, which is used for fine tuning or adjustment, as will be described in greater detail hereinafter.

The rod I9! is enclosed by a tube iii-3 having a threaded portion I04 which meshes with the screw threads of the rod mi. The outer end of the tube 103 is connected with a cover H15 whichis located close to the knob 21a and which is in-- tegral with a handle I96. The inner endof the rod Hll' carries a pin I91 which extends through an opening rovided in the tube 163. The outer end of the pin it! is located close to an edge of a sleeve Hi8. As shown in Figure 1 the sleeve N18 has two notches, W9 and I I9. These notches are adapted to receive the pin Nil.

The operation of the machine is as follows:

When the switch 28 is switched on, the motor 25a, is energizedby the electric current flowing 5 through the Wires 3 I. The turning of the switch 30 will energize the magnet 55 which will provide a driving connection between the motor 25 and the drum II through the shaft 32 and the wheels 39, 31, 42 and II.

The electric rectifier section of the machine, which includes a rectifier tube 2|, transformer 23 and a fuse 24, is of standard construction and does not constitute a part of the present invention.

It should be noted in this connection that the plate 61 constitutes a rigid support for one end of the spindle 20, while the spring I8 constitutes a support for one end of the drum II.

As already stated, the magnetic sheet 50 is carried upon the drum II with its end 82 within the slot I0. The sheet is held in this position by the wheel 92 and the fingers 95 to 99.

The rotation of the drum II is transmitted to the spindle 20 through the gears I6, 19 and 65. Since the sound head I? is in engagement with the spindle 20 through the pawl 54, the sound head i! will move along the drum I I and will inscribe a helical sound track upon the magnetic sheet 50, as well as reproducing an inscribed track into sounds by the usual play-back system, not shown in the drawings. The change from recording to play-back, and vice versa, is carried out by the switch 29a.

The user may stop the machine instantaneously by operating the switch 28. He can shift the sound head II, step by step, backward in relation to the drum I by operating the transverse rod 29 which will raise the follower 54 from contact with the threads of the spindle 20, thereby making it possible for the spring-tensioned wire 56 to pull back the sound head H. To move the sound head I 'I, at will, either forward or backward in relation to the helical track on the drum I0, the operator simply depresses the plate using the knob 5I9 that extends above the cover of the machine.

In accordance with the present invention, the user can place the sound head II in a space between two tracks inscribed, or about to be inscribed, thereby creating a second track merely by turning the lever I06.

Since the lever I06 is integral or firmly connected to the tube I03, the tube will turn along with the lever. Since the pin IN is firmly connected to the rod II and extends through an opening formed in the tube I03, the rod IOI will participate in this turning motion. The function of the spring I02 during this operation is to prevent relative movement between the threads of the rod II and the threads I04 of the tube I03. Since, as shown in Figure l, the notches I09, IIO are located at difierent distances from the plate 09, and since the turning of the lever I06 will cause either a forward or rearward movement of the rod I02, it is apparent that the two end positions of the pin I0! will correspond to different positions of the plate 66, which is always maintained in contact with the spherical end I06 of the rod IN by the spring 10.

Thus, two different tracks are produced by moving the pin I01 from its position in one of the notches I09 or IIO to a position within the other one of these notches.

Since the plate 69 is rigidly connected to the plate 61, which presses against the end 66 and the spindle 20, it is apparent that the two positions of the plate 69 correspond to two positions of the spindle 20, which is pressed against the plate 6'! by the spring 62. Thus, the turning of the lever I06 causes a longitudinal shifting of the spindle 20, and the two end positions of the tance between these two end positions is substantially equal to one-half of the pitch of the helical sound track, so that the second sound track will be located substantially in the middle of the first track.

It is apparent that the operator can use the second sound track for interlineations or additions to the originally dictated text. In that case the beginning of the additional text may be indicated upon the original track by a sound signal.

On the other hand, the user might employ the second sound track in its entirety to provide a text running parallel to the original text. This may be utilized, for example, by employing the while the change from recording to play-back,

sound track at a somewhat different location than another machine.

This fine adjustment is carried out by turning slightly the knob 27a. Since the rod IOI is firm- IOI mesh with the screw threads I04 of the tube I03, the rod IOI will carry out a movement in the direction of its longitudinal axis. This movement is transmitted to the plate 69, which is in connected with a plate 69. show a somewhat different mechanism for operating the spindle 20 which, as in the previously described construction, has a spherical end 66 engaged by a plate 61 which is integral with the plate 69. The plates 67 and 69 are mounted upon a column 68 and the plate 69 is pressed against the inner end of a rod 20I by a spring I0. The outer end of the rod MI is connected with a knob 21a. The rod 20I is somewhat different in construction from the rod IOI (Fig. 2) since the rod 20I has a comparatively small, intermediate, threaded portion 2I0 which is engaged with corresponding screw threads 204 of a rectangular casing 203. The casing 203 is firmly connected to the positioning handle I06. The rod 20I has a reduced portion which is enclosed by a spring 202. As shown in Figure 4, the member 203 has a threaded portion 2I4 which meshes with the screw threads 2I5 of a supporting bracket 2I6. The bracket 2I6 is connected by screws 2I I to a frame I3.

Springs 2I8 are attached to the support 2I6 and 1 are "pressed :byqa :xcoiledv spring 2 I9 :aga'inst opposite sides of the rectangular-.member 1-203. The support-2H5 .has a front portion 220, the upper edge-of which is engaged :by a':sto,p;22l. The stop TM is integral :with;-aflange:222-connected to the casing 203.

It is apparent that :the lever 1.00 may-ebeoperated to shift the;stop Hi :.from the position shown in full lines in Figure .5'tothe position shown in broken lines thereon, and vice versa. In the course of this movementzthecasing Y203 and the rod 20! wilt-move longitudinally, thereby shifting the position of (the plate 69 and, consequently, changing the position 'of the spindle 20. The springs202 and 2 l8 inthis construction perform a function similar to the spring [02in the constructionshown in Figure 2, namely, they prevent relative movement loetween screw-threads 2 I and '2 04 during: the shifting; from ionexsound track to another.

The fine adjustment to ,an ;inscribed sound track is carried out by turning :zthe knob 21a with the result that the. pin :20l'will-turn inrelation to the screw threads .'204,::and willcarry out the movement in the longitudinal direction, thereby shifting the positions of the platesl60 and B1, and of the spindleZD.

The twodescribed constructions aprovide means for shifting the spindle 20in .order to change from one sound track toa-secondsound track. The construction illustratedin Figure :6 provides mechanicalmeans for shifting the :position of the drum H forthe samev purpose. This drum maybe of the. same construction asthe one previously described, and may be provided with a knurled flange l6 and alpivotjcarrying :a spherical endi11 and a gear 16 which meshes with the'gear 19l The opposite'end :of the drum ll (not shown) is engagedcloy aspring .similar to the spring 14 shown in Figure 1.

In accordance with the present invention; the member 318, which engages the end.j11, hasrthe form of an elongated plate which 'iSlIJlVOtZJl-IY supported intermediate its ends. by a pivot 300. The pivotf300 is mounted ina bracketz30l which is attached" to suppor 313.

The opposite end of 'the plate318 is engaged by a cam3c2 which: is keyed ,upon.a;-shaft;303. The shaft 303 is supported in bracketst304. and 305, carried by the support, 31-3. The outer end of the shaft 303 carries a lever-306.

The lever 306 may be situated inv two positions, limited by the cross rod -303a,-namely, an upper and a lower position. When the :lever is turned from the upper position, shownin- FigurelG, to its lower position; the cam 302 will rotatealong with the shaft 303,.and will turn the plate: 318 :so that the upper end ofthe plate 318 will push against the pivot of the drum ll. Thus,;it,1is [apparent that the turning-of the lever 306-willchange; the position of the drum ll, andxthat. thetwo end positions of the drum will :be'determinedtby theshape of the cam 302.

In theconstruction shown in Figures hand 8, the same shifting of the drum' l lywhichrcauses the changeover from one: soundtrack to. another, is carried out: by magneticcmeans. The drum l I may be of the same construction as the ones previously described, and may have a flange IS, a pivot-15 carrying 'a-gear 16, and' a-spherical end 11. A plate'418 is pivotallyemounted intermediate its ends upon a pivot 400:..carried \by a bracket'40l. The bracket 40l iszcarried;by;thesupport 4l3. -A bolt -402 extends throughan openingprovided in the :plate 41 Band. is screwed into the support M3. A coiled spring 403 encloses the :bolt 402 and presses with oneend against the support M3, and with the other end against the plate 412. The plate .418 consists of any suitable magnetizable material which may be attracted by magnet 404.

In this construction the shifting from one trackto another is accomplished by energizing themagnet'404 by means of any suitable switch, not shown in the drawings. The magnet 404 will attract ,the'plate 41-8 until it strikes the end 405 of gtheamagnet. The drum II will be compelled to follow the plate 418 by the pressure of a spring (not shown) exerted upon the opposite end of thedrum. Thisturning movement of the plate 418 will compress the spring 403.

As soon as the magnet404 is ole-energized the spring 403 will push the plate 418., along with the drum ll,-into the initial position shown in Figure 8. It is thus .apparentzthat in accordance with this construction the magnet-404 causes the shiftingrof thedrumll into one of two positions corresponding to. two different sound tracks.

Figures 9 to 12 illustrate -at mechanism wherein the shifting to one of two sound tracks is carriedqout by operating the sound head 11. As already stated,the soundhead i1 is carried by a support I 8 which is attached .to a carriage 51. The carriage 5! includes wheels 53 and-.53 which are mounted upon the rod IS. The engagement between the sound head l1 and the spindle 20 is effected byzthe follower 54 which is rotatably mountediupon a pivot 36. The follower 54 is engaged :byv a spring 4|, one end of which is attached toa pin ,502. Theopposite end'of the spring 50l is-attached to .a pin 503 carriedbya plate 34. The plate-34 has, two elongated slots 505 and- 506 through which extend the pivots 501 and 508, respectively. The plate 34 is integral with the follower arm-31a. The. plate 34 carriesan ear5l0 towhich one end of the spring 5!! is attached. The opposite end ofthe spring 5 is attachedto a pin;5l2- carried by the carriage 5|.

'The;follo,wer 54' has jutting, cam-like surfaces whichaareadapted to be engaged by pins 38.and 39a, which are carried by-the plate 34.

The ,useof the two, followers 31a and 54 is described ,and {claimed inthe aforesaid "patent application of Keller and, Sigrist.

.Intheyillustrated construction the top surface of the carriagefil lhasvthe form of .a V- shapedsgroove 'whicheontains apin-5l6. The pin1-5l6 .is ,carriedbyarod 5l5 which extends through the carriage .51, and the lower end of which ,is firmly. connected with the pin-or pivot 36. Asshownflin Figure 10,;the lowerend of the pin 36pprojects belowv the followers 54 and 31a, and is embraced by theqcoiled; spring 5l1, which rests upon a disk-shaped end, 518 of the pin 36. The upperzendnof the rod 515 carries a knob 519 which is firmly attached thereto by the screw 520.

The-operationof this mechanismis apparent from the above description:

,In the position illustrated in thedrawings, the sound head l1.is r,eady to inscribe one of ;the sound tracks. Inorder to shift to another sound track the user grasps the knob 519, pulling the rod 5l5 and -the pin.36, and thereby compressing thespring 5l1. Then the user turns the knob 5-l9.;\unti1 the; pin 5l6 is turned to the extent of whereupon his grip on the knob 5l9 is released; and the pin rests again "in the, -V -shaped grooyeof the carriage 5|. Since the pin 36is eccentrically mounted in the rod '5l5, ing of the the turn rod l5 will cause a movement of the ample, in Figure 13 of the drawings, and which includes a knob 621, which is firmly connected with a rod 601. The rod 60! has screw threads meshing with the screw threads 604 of an inner tube 509. The inner end of the rod 60! engages a plate 69, which is pivoted at 68 and is firmly connected with the plate 61. The plate 61 engages the end 66 of a spindle 20.

It is apparent that the examples shown above have been given by way of illustration and not by way of limitation, and that they are subject to wide modifications and variations without departing from the scope or intent of the present invention. All such modifications and variations are to be included within the scope of the present invention.

What is claimed is:

1. In a sound recording and reproducing machine, a sheet-carrying drum, a threaded spindle extending parallel to the axis of said drum, sound head means comprising a follower engaging the threads of said spindle and a recording head engaging a magnetic sheet wrapped around said drum and rotatable therewith to record and reproduce a sound track on said sheet, means connected with said drum and said spindle for rotating them, whereby said sound head means are moved along said spindle during the recording and reproducing, a spring engaging one end of said spindle and pressing it toward the other end thereof, a plate engaging said other end of the spindle, another plate firmly connected with the first-mentioned plate, means pivotally supporting said plates, a rod having an end engaging other plate, and means shifting longitudisaid rod, whereby the position of said spindle is varied in the direction of its axis and the position of said sound head means upon said sheet is adjusted.

2. In a sound recording and reproducing machine, a sheet-carrying drum, a threaded spindle extending parallel to the axis of said drum, sound head means comprising a follower engaging the threads of said spindle and a recording head engaging a magnetic sheet wrapped around said drum and rotatable therewith to record and reproduce a sound track on said sheet, means are moved along said ing and reproducing, a spring engaging one end of said spindle and pressing it toward the other end thereof, a plate engaging said other end of the spindle, another plate firmly connected with the first-mentioned plate, means pivotally supporting said plates, a rod having a threaded portion and an end engaging said other plate, a tube having threads meshing with the threaded portion of said rod, whereby a turning of said rod will shift it longitudinally, and means connected with said tube for turning said tube jointly with 10 said rod to a plurality of predetermined positions corresponding to predetermined sound tracks upon said magnetic sheet.

3. In a sound recording and reproducing machine, a sheet-carrying drum, a threaded spindle extending parallel to the axis of said drum, sound head means comprising a follower engaging the threads of said spindle and a recording head engaging a magnetic sheet wrapped around said drum and rotatable therewith to record and reproduce a sound track on said sheet, means connected with said drum and said spindle for rotating them, whereby said sound head means are moved along said spindle during the recording and reproducing, a spring engaging one end of said spindle and pressing it toward the other end thereof, a plate engaging said other end of the spindle, another plate firmly connected with the first-1nentioned plate, means pivotally supporting said plates, a rod having a flange, a threaded portion and an end engaging said other plate, a tube enclosing a portion of said rod and having threads meshing with the threaded portion of said rod, whereby a turning of said rod will shift it longitudinally, a pin carried by said rod, and extending through an opening formed in said tube, a spring located within said tube and engaging said flange, and a sleeve comprising an edge having a plurality of notches adapted to receive an end of said pin, whereby the positions of said pin correspond to predetermined sound tracks upon said magnetic sheet.

4. In a sound recording and reproducing machine, a sheet-carrying drum, a threaded spindle extending parallel to the axis of said drum, sound head means comprising a follower engaging the threads of said spindle and a recording head engaging a magnetic sheet wrapped around said drum and rotatable therewith to record and reproduce a sound track on said sheet, means connected with said drum and said spindle for rotating them, whereby said sound head means are moved along said spindle during the recording and reproducing, a spring engaging one end of said spindle and pressing it toward the other end thereof, a plate engaging said other end of the with said tube, a frame, and means connected ERNST KELLER.

References Cited in the file of this patent UNITED STATES PATENTS Niunber Name Date 479,431 Lahola July 26, 1892 511,402 Bruening Dec. 26, 1893 1,792,159 Gonzalez Feb. 10, 1931 2,003,434 Goldhammer June 4, 1935 2,043,884 Crudo June 9, 1936 2,082,353 Proctor June 1, 1937 2,284,043 Clausen May 26, 1942 2,410,569 Conant Nov. 5, 1946 2,530,029 Pond Nov. 14, 1950 

